The return of "Pretty Little Liars" is always a social occassion. Such was the case last night when The Paley Center for Media hosted "Pretty Little Liars: #PLL is @PaleyCenter," a special preview of the highly anticipated fourth season premiere followed by a panel with the cast and creative team. Our Amir Talai was on hand to get the scoop from executive producers I. Marlene King and Oliver Goldstick as well as actor Tyler Blackburn, who will be transitioning to the show's spin-off "Ravenswood" in October.